This is an interdisciplinary study of how the central nervous system recovers after focal or diffuse trauma. The classical view of neurological functions based on focal lesion effects will be supplemented by our analysis of the diffuse lesion effects produced by closed head injury where the centripetal theory of cerebral concussion is used to predict lesion locations. Methods used include neuropsychologic testing, averaged evoked potential recording, transmission and emission computerized tomography and neurophysiologic recording in humans and sub-human primates.